Transactions on micronuclear DNA and implications for immune signaling

Nuclear envelope formations on missegregated chromosomes or chromosome fragments produce micronuclei. Although they exist largely in an autonomous state, they maintain aspects of chromosome biology that are found in the major nucleus. Aberrant micronuclear envelope behaviors alter communication with the cytoplasm. Micronuclear envelope rupture exposes entrapped chromosomes to DNA-interacting factors, resulting in DNA damage and massive chromosome shattering. Exposure of micronuclear DNA to innate immune sensors has been proposed to trigger inflammatory cytokine production. Such events can direct tumor microenvironments in response to genotoxic therapies. Understanding the formation, rupture, DNA integrity, and detection of micronuclei by immune sensors will provide insights into human disease and suggest approaches for therapeutic intervention. Here we discuss basic studies on micronuclei stability and transactions that affect their chromosomal DNA content.